Spectrofluorometric Determination of Iron II Based on the Fluorescence Quenching of Cadmium/Tellurium Quantum Dots

Water-soluble and stable CdTe quantum dots were synthesized in aqueous solution with thioglycolic acid as the stabilizer. A spectrofluorometric method for the determination of iron (II) has been developed based on quenching of the fluorescence of CdTe quantum dots by iron (II) in aqueous solutions. It can perform an accurate and simple determination of iron (II) concentration in water samples. Under optimum conditions, the quenched fluorescence intensity increased linearly with the concentration of iron (II) ranging from 5.0 × 10−8 to 4.0 × 10−6 mol/L with a correlation coefficient R = 0.9969. The limit of detection for iron (II) was found to be 1.2 × 10−8 mol/L. As an application, the proposed method was successfully applied to the analysis of iron (II) in water samples, and the results were satisfactory.